Images of Missiles at Sea Set Off Debate Over Iran Threat

Hanging over the current disagreement is the debate over the Iraq war and, specifically, Secretary of State Colin L. Powell’s address to the United Nations in 2003. Mr. Powell’s presentation included fuzzy images and partial communications intercepts, and detailed what came to be understood as wildly wrong assessments to weave together an inaccurate picture of the Iraqi government’s illicit weapons.

In the current debate, Representative Seth Moulton, Democrat of Massachusetts and a Marine veteran who served in Iraq, has introduced legislation to require the Trump administration to get congressional approval before “engaging in hostilities” with Iran. In April, Senator Rand Paul, Republican of Kentucky, pressed Mr. Pompeo during a hearing for the same commitment, but the secretary of state deflected the request.

Most Republicans signaled they supported the administration’s tough line. “Iran seems to be more aggressive and we have to push back,” Senator Richard C. Shelby, Republican of Alabama and the chairman of the Appropriations Committee, said after meeting with intelligence officials. “We cannot give them a lot of space.”

The divisions over the intelligence extended to American allies.

Troops from Germany and the Netherlands were pulled back to bases in Iraq. Spanish defense officials withdrew a frigate that was part of the American-led carrier strike group heading to the Persian Gulf to avoid entanglement in any upcoming conflict with Iran.

But the training efforts by France and the North Atlantic Treaty Organization are continuing as normal.

The State Department ordered “nonemergency U.S. government employees” at both the embassy in Baghdad and the consulate in Erbil to leave the country. The order applied primarily to full-time diplomats posted to Iraq; an embassy statement said that visa services in Iraq would be suspended as a result. Contractors who provide security, food and other such services will remain in place for now.

Mr. Pompeo shared some details of the intelligence with Iraqi leaders on May 7 when he made a surprise visit to Baghdad. But American officials in Washington said the most delicate intelligence was not shared with the Iraqis for fear their agencies have been penetrated by Iranian spies.

Tensions with Iran have been rising since May 2018, when Mr. Trump withdrew the United States from the 2015 nuclear deal that world powers reached with Tehran. American sanctions were reimposed in November, weakening the Iranian economy — perhaps more quickly than expected.